Hypodermic needle



Jan. 16, 1940. G. E. BARNHART HYPUDERMIC NEEDLE Filed July 11, 1 956 s Sheets-Sheet 1 IN VENTOR.

A ORNEY.

- Jan. 16, 1940. G E BARNHAR-T 2,187,259

' HYPODERMIC NEEDLE Filed July 11, 1936 3 Sheets-Sheet 3 1 37 3a '28 2a 35 36 2f 53 v v 20 INVENTOR.

GEORGE E. .BARNHART.

Patented Jan. 16, 1940 UNITED STATES PATENT OFFICE HYPODEBMIC NEEDLE George E. Barnhart, Pasadena, Calif.

Application July 11, 1936, Serial No. 90,135

.8Claims.

This invention relates to hypodermic needles.

The general object of the invention is to provide an improved hypodermic needle for injecting anaesthetics as, for example, that used by dental surgeons and by physicians for intravenous injections. 1

Another object of the invention is to provide an improved depth gauge for use with a hypodermic needle.

Another object of the invention is to provide an improved quick injection device for a hypodermic needle.

Another object of the invention is to provide an improved welding device and die for use in making a lrvpodermic needle.

Another object of the invention is to provide a hypodermic needle which is harder at the tip than at the base and wherein the needle may be made progressively harder from the base to the tip by cold working.

Another object of the invention is to provide a novel hypodermic needle which may depend for its hardness exclusively upon working, with the work preferably a drawing action.

A further object of the invention is to provide a hypodermic needle which has greater strength at the base than at the tip and wherein the grain structure is so disposed that maximum strength results may be secured and wherein the greatest strength against lateral bending is secured.

Another object of the invention is to provide a hypodermic needle made of a novel tapered sheet or other blank and wherein preferably the proper thickness is provided in the needle before the latter is formed, thus permitting the sheet or tube to be tapered longitudinally before forming Another object of the invention is to provide a needle which varies its outside diameter but which is of uniform strength throughout its length and which has a greater cross section at the base than at the point.

Another object of the invention is to provide a hypodermic needle which is so constructed that the bending strains are gradually transferred into the base.

Another object of the invention is to provide an improved hypodermic needle having a smaller tip than has heretofore been practiced with a normal size base. 7

Another object of the invention is to provide a hypodermic needle which is drawn to close the seam and is further drawn to cause an elongation of the metal.

Another object of the invention is to provide a tapered needle which may be seamless or which may include an abutting or welded seam wherein the material is hardened due to the working operation. 6

Other objects and the advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings, wherein:

Fig. 1 is a side elevation of a hypodermic l0 needle and quick injection device embodying the features of my invention;

Fig. 2 is a central, longitudinal view through the needle shown in Fig. 1 with parts broken away;

Fig. 3 is an enlarged, fragmentary, sectional view through the end of the needle;

Fig. 4 is a section taken on line 44 of Fig. 2;

Fig. 5 is a section taken on line 5-5 of Fig. 2;

Fig. 6 is a plan view showing one form of blank 20 from which my improved hypodermic needle is made;

Fig. 7 is an enlarged, fragmentary view taken on line 'I--| of Fig. 6;

Fig. 8 is a central, sectional view taken through a modified form of hypodermic needle;

Fig. 9 is a section taken on line 99 of Fig. 8:

Fig. 10 is a side elevation showing a modifl form of needle and a depth gauge;

Fig. 11 is an enlarged, fragmentary view show- '0 ing the modified needle and gauge;

Fig. 12 is a side elevation showing a further modified needle;

Fig. 13 is an enlarged, fragmentary, central. sectional view through the needle shown inFig. 85 12;

Fig. 14 is a section taken on line -44 of Fig. 13;

Fig. 15 is a view similar to Fig. 12 showing a further modification;

Fig. 16 is a fragmentary, central, sectional view showing the modified needle of Fig. 15;.

Fig. 17 is a view similar to Fig. 16 showing a further modification;

Fig. 18 is a central, sectional view of a further modified needle;

Fig. 19 is an end view showing the manner in which the blank of Fig. 6 is first formed;

Fig. 20 is a fragmentary, side elevation of the blank formed as shown in Fig. 19;

Fig. 21 is a central, sectional view through a forming die; v v

Fig. 22 is a top plan view of the forming die;

Fig. 23 is an end view, partly in section, showing the welding apparatus;

' ters I have shown my invention as embodied in a hypodermic needle which is indicated generally at I0. As shown this needle is preferably made from a blank I I shown in Fig. 6 and which blank' includes a thickened end portion 12, a bevelled portion l3, and an end portion l4.

In the practice of my invention the blank II is preferably formed to the shape shown in Figs. 19 and 20 by forming it over a mandrel, for example, in a brake. The blank formed into the shape shown in Fig. 19 may then be passed through a circular die opening IS in a taper die element shown at IS in Fig. 21 or through the die opening 51 shown in Fig. 23. A suitable comealong device l1 may be employed, also a mandrel |8 may be used within the die.

After the edges have been brought to closely abutting relation the formed tube may be passed through a welding apparatus shown in Fig. 24, wherein thedevice includes a bottom roller 28 which has a tapered groove 2| in its periphery corresponding to the taper of the tube and a pair of top rollers 22 and 23 which are positioned in the opposite side of the seam 24. The rollers 22 and 23 have tapered grooves 25 and 26 therein which correspond to the taper of the tube. The bottom roller 20 is mounted on a shaft 21 which is arranged on a suitable support 28 and has a gear 29 thereon. Above the shaft 21 I arrange another shaft 30 on which a gear 3| is mounted. This gear meshes with the gear 29 previously described. Either the gear 29 or the gear 3| may be suitably driven.

The shaft 30 includes a universal 33, which drives the shaft 34 of the roller 23 and the shaft 34 includes another universal 35 which drives the shaft 36 of the roller 22. The shafts 34 and 36 are suitably mounted on supports 31 and 38. The supports 31 and 38 are of metal and are mounted on insulation material 39 and the supports are connected by wires 40 and 4| to a suitable source of electric current so that this current passes to the rollers 22 and 23 which are disposed on opposite sides of the seam thereby producing an electric weld at the seam. The shafts 34 and 36 are suitably insulated from the current.

After the seam is welded or even before it is welded the tube is passed through a forming die such as shown in Fig. 23. This die comprises a plurality of rotatable die elements 46 preferably four in number, some of which are keyed on spindles 41 and others on shafts 48 on a support 49. These die elements are geared through gears 60, 5|, 52, and 53 so that they rotate together. The dies are adapted to be driven by a gear 54 from a gear 55 which may be driven by a gear 55' from a rack 55" or in any suitable manner.

The dies 46 are provided with peripheral grooves 56 which are similar in shape and of similar taper and the dies are arranged so that they are tangent to each other and their faces meet at an angle of 45 so that the die opening 51 is formed through which the tube is drawn or passed. I now prefer to draw the tube through the die opening by starting the tube with its largest diameter in pressure engagement with the largest portion of the die opening and then rotating the die in advance of the tube as the die advances.

If preferred the die 68 shown in Fig. 25 may be employed where it is desired to produce a bead 6| or a groove 62 in the hypodermic needle, but it will be understood, of course, that a configuration other than that shown in the die mechanism may be employed without departing from the spirit of my invention.

The die shown is of such a shape that it will draw the tube which approximates the general shape shown in Fig. 1 prior to the drawing into the shape shown in Fig. 1. It will be understood, however, that prior to the drawing action the tube may have a. shape which differs much from that shown in Fig. 1. In other words the amount of. draw will vary with the particular requirements of the hypodermic needle to be manufactured.

After the tube is drawn it is provided with a base member 18' which as shown in Fig. 1 includes a body having a recess H in which the end of the needle is fixed and has a reduced cylindrical portion 12 with a collar 13 thereon. The base includes a hollow portion 14 which communicates with the interior of the needle. The forward portion of the needle is bevelled on the line indicated at 15 to sharpen it and may also be provided with plane bevel portions 18 and 11 to provide a novel point to facilitate injection.

The needle shown in Figs. 1 and 2 is also provided with an injection device indicated generally at 88. This device includes a pair of spaced engaging members 8| mounted on opposite sides of the needle. These engaging members are engaged by the reduced end 82 of a coil spring 83 which on its forward end is secured as by soldering to a head 84 having a groove 85 therein which acts in the nature of a suction cup while the head is provided with a pair of rearwardly extending arcuate arms 86 which as shown in Fig. 4 are disposed between the engaging members 8!.

The arms 86 have a bevelled front end as at 81 and they are of such a size that when the device 84 is moved rearwardly the arms 86 are placed between the members 8| and the bevelled portions 81 and engage under the coil 82 of the spring 83 thus raising this coil above the members 8| whereby the coil is free to move along the needle. The needle is provided with a stop member 81 which is adjustable along the needle, being held in place by a screw 81 The stop member limits the movement of the arms 86 and thus determines the depth of injection.

In the invention shown in Figs. 1 and 2 the needle includes the thickened portion 81 which is attached to the base 10. The portion 81 is connected to a tapering portion 88 the wall thickness of which tapers. The portion is secured to a. cylindrical portion 89 of uniform wall thickness. This cylindrical portion 89 terminates in a beveled portion 90 which is shown as of uniform wall thickness and this portion 98 terminates in a cylindrical portion 9| the end of which is pointed as previously described.

In the operation of my invention the needle I0 is mounted on a suitable syringe and when an injection is to be made the member 85 is placed over the area to be threaded and pressure is applied by moving the syringe and needle l8 towards the member 85. The member 85 moves towards the needle portion 89 until the bevelled face 81 passes beneath the coil 82 lifting the coil 82 from the members 8| whereupon, due to the pressure necessary to compress the spring 83, the needle jumps forward and into the patient so that the desirable quick jabbing action essential in local anaesthetizing is secured with uniform pressure and piercing and thus with the stop member 31'- employed uniform injection is secured under all usual conditions.

In Fig. 8 I show a modification of my invention wherein the head I'is provided with a needle IN. This needle IOI includes a cylindrical portion I02 of uniform wall thickness which is connected to a tapered portion I03 which is of increasing wall thickness towards the smaller portion and this portion I03 is connected to a portion I04 which is cylindrical and is of uniform wall thickness and this portion I04 is connected by a tapered portion I05 of uniform wall thickness which in turn is connected to a tapered portion I06. This portion I06 is of general cruciform shape which is shown in Fig. 9 and includes outer portions I01 joined by reversehr curved arcuate portions I08.

This construction gives a very rigid, firm needle for a deep injection while at the same time the maximum periphery of the puncture is'not increased so that in certain types of injection a very desirable effect is secured.

In Figs. 10 and 11 I show a modification of my invention wherein the needle indicated genorally at H0 is mounted in the base III and the needle at one end includes a cylindrical portion of uniform wall thickness as at H2, a taper portion II3,'and an end portion II4, both of which are of uniform thickness and the forward end of which is pointed as at II5. At the other end the needle includes a tapered portion 5' which is shown as sharpened so that it may be used to pierce an ampule cork or for other purposes.

The portion H5 is provided with a peripheral groove H6 in which the end wall I" of a spring H8 is mounted. The forward end of the spring II8 has an annular member II9 secured thereon as by soldering. I show a rubber suction cup I Iil on the member I I9. This cup H3" serves to hold the needle in the desired locality and also serves to stretch the skin of the patient. In operating after the suction cup is in place it is pierced by the needle as it advances into the patient. After each injection a new cup is placed on the member II9. In the use of the modified form of my needle the usual injection is made and the spring member II8 acting in conjunction with the member IIB serves to limit the depth of the injection.

In Figs. 12 and 13 I show a modification of my invention wherein the needle I20 includes an end portion I2I which is fitted in a base I22. The portion I 2| is cylindrical and of uniform wall thickness and is connected to a protuberant portion I23 the outer surface of which is rounded. The portion I22 is connected to a portion I23 which uniformly tapers forwardly to a location I24 whence the needle gradually assumesan oval position as shown in Figs. 13 and 14 at I25. At

this point the needle is pointed as at I 26 and is provided with peripheral grooves I21 which serve as vents to allow surplus solution to escape from the injection puncture.

In Figs. and 16 I show a modification of my invention wherein the needle includes a frustoconical portion I 30 which is connected to a cylindrical end portion I3I. The frusto-conical portions merge into a forward portion I32 which is tapered but at less degree than the portion I30 while the portion I30 is continuous to an end portion I33 which is bevelled as at I34.

The needle shown in Fig. 17 is similar to that shown in Fig. 16 except that the portions I30, I3I', and I33 are all of uniform wall thickness and are provided with a forward pointed portion I3 The needle shown in Fig. 18 includes an end portion I40 which is fitted in a base I. The forward end of the needle portion tapers at I42 to a portion of minimum diameter I43 whence the needle cross-section increases to a location I44 whence it again decreases at a point I45. The needle shown in Fig. 18 has a circular periphery and the inner portion is uniform throughout so that the needle wall varies. The location I44 may be advanced from the point I45 depending upon the purpose for which the needle is to beused.

It will be understood that the needles embodying the features of my invention may be made of suitable material such as gold, platinum, stainless steel, or various alloys. The material with which the needles are made may be worked cold to cause the material to harden or the needle may be heat treated. I now feel that it is preferable to have the small sharpened end hard and the larger end soft. In this case the larger .end should have more strength to prevent breakage due to the softer condition.

The strength of the larger end may be increased by an increase of metal or by increasing the diameter over that of the sharpened portion, that is, the larger end may have a greater section modulus than the sharpened portion or a greater moment of inertia by having a greater moment of inertia in the larger portion than at the sharpened portion. By making the sharpened portion harder and the larger portion of increased size a needle of greater strength may be provided yet the needle will have greater resistance to crystallization than a needle of uniform moment of inertia and uniform hardness.

It will be seen that with my invention the strength can be secured where desired and the wall thickness can be controlled so that the maximum of injection efilciency can be secured.

Having thus described my invention I claim:

1. A hypodermic needle including a plurality of stepped portions with the portion comprising the smallest step having a thicker wall than the other portions.

2. A hypodermic needle including a plurality of stepped portions with the portion comprising the smallest step having a thicker wall and being harder than the other portions.

3. The combination of a hypodermic needle having a groove therein and a depth regulating member including a coiled spring, said spring having a loop fitting said groove, said spring having a flesh engaging annular member thereon remote from the needle, said flesh engaging member directly engaging said spring.

4. ma hypodermic needle, the combination of a needle and an injection actuating device, said I device including a, spring engaging the needle, spring release means shiftable to release the needle and adjustable means on the needle and coacting with said device to limit the depth of the injection.

5. In a hypodermic needle, a base and a. needle member, said needle member comprising an integral body including a cylindrical portion secured to said base, a bevelled portion on said cylindrical portion, said bevelled portion having its wall thickness increasing away from said cylindrical portion, a second cylindrical portion on said bevelled portion. a second bevelled portion of uniform thickness on the end of said second cylindrical portion and a third cylindrical portion on the end of said last mentioned bevelled portion.

6. In a hypodermic needle, the combination of a needle and an injection actuating device, said needle having a pair of spaced engaging members therein and said device including a collar, said collar having a spring thereon, said spring at the end remote from the collar including one coil engaging said needle adjacent to said engaging members, said collar having a pair of spaced arms thereon, said arms being adapted to fit between said engaging members, said arms having their ends bevelled, said arms being movable to a position beneath said one coil whereby to cause one coil to expand to free the spring.

'7. In a hypodermic needle, the combination of a needle and an injection actuating device, said needle having a pair of spaced engaging members therein and said device including a collar, said collar having a spring fixed thereon, said spring in the end remote from the collar including one coil engaging said engaging members, said collar having a pair of spacedarms thereon, said arms being adapted to flt between said engaging members, said arms having their ends bevelled, said arms being movable to a position beneath said one coil whereby to cause one coil to expand to free the spring and adjustable means on the needle to limit the movement of the arms to thereby limit the depth of the injection.

8. In a hypodermic needle, a base and a needle member, said needle member comprising an integral body including a cylindrical portion secured to said base, a bevelled portion on said cylindrical portion, said bevelled portion having its wall thickness increasing away from said cylindrical portion, a second cylindrical portion on said bevelled portion, a second bevelled portion of uniform thickness on the end of said second cylindrical portion and a third cylindrical portion on the end of said last mentioned bevelled portion.

GEORGE E. BARNHART. 

